Spread vs Center Statistics Example 4

Follow the full solution, then compare it with the other examples linked below.

Example 4

medium
Two classes both have median score 75. Class A scores are 72, 74, 75, 76, 78. Class B scores are 60, 70, 75, 80, 90. Which class has greater spread, and which class seems more consistent?

Solution

  1. 1
    Step 1: Range of Class A is 78−72=678 - 72 = 6, while range of Class B is 90−60=3090 - 60 = 30.
  2. 2
    Step 2: Class B has the greater spread, so Class A is the more consistent class.

Answer

Class B has greater spread, and Class A is more consistent.
Spread tells us how much the scores vary, even when the center is the same. A smaller spread means the data is more tightly clustered and therefore more consistent.

About Spread vs Center

Center describes where the 'middle' of data lies; spread describes how far data extends from that center.

Learn more about Spread vs Center →

More Spread vs Center Examples

Example 1 medium

Two machines fill bottles. Machine A fills: 500, 502, 498, 501, 499 mL. Machine B fills: 490, 510, 4

Example 2 medium

Dataset A: {10, 10, 10, 10, 10}. Dataset B: {2, 6, 10, 14, 18}. Compare their centres and spreads.

Example 3 medium

A restaurant's lunch wait times (minutes) — Week 1: 5, 6, 5, 7, 5. Week 2: 3, 10, 4, 8, 3. Find the

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